1. Field of the Invention
Embodiments of the invention generally relate to piezoelectric transducers. In particular, embodiments relate to the in situ testing of piezoelectric transducers.
2. Discussion
On occasion, anomalies may appear in the highly dynamic test data obtained during rocket engine tests. Each data anomaly occurring during a test program is typically investigated and appropriate corrective action may be mandated before the test program is permitted to continue with subsequent testing. Due to condensed test schedules, only a few days may be generally allotted for identifying the cause of any anomaly and performing a corrective action.
A typical challenge might be the appearance of spurious signals in accelerometer data channels, wherein the origin of those signals may be unknown. An assumption might be made that the spurious signals have been caused by loose or broken accelerometers. In such a case, technicians might be sent to remove the accelerometers from the test article and check the mounting torque. The result could be the replacement of several transducers and costly delays. In some cases, only a small number of the accelerometers may be identified as defective, and the cause might never be conclusively identified. Simply put, it may often be unclear whether anomalies in recorded signals are due to differences between the data acquisitions systems, differences between the accelerometer, a failed accelerometer, or whether everything is working correctly and the systems are accurately recording real events. Indeed, currently, signal simulators, shakers, static pressures simulators, and in-house calibration systems may all be employed for monitoring the instrumentation components. Any component with questionable performance, i.e., anomaly present, may be sent out for extensive testing and high-quality calibration. In addition, all the instrumentation accelerometers can be put on a rotational calibration schedule to be removed and sent off to a calibration laboratory, which can further add to costs and delay.